Monitoring of communications by user equipment units (UEs), network elements (NEs), and other system elements is an increasingly important function. Performance monitoring can enable a network operator to identify bottlenecks and take appropriate actions to improve communication quality. An operations support system can monitor performance using coarse resolution data that has been separately aggregated by network elements to provide a performance metric (e.g., the total number of dropped calls in a cell).
In contrast, signal tracing is another form of monitoring that can provide much more detailed information for a user call. The operations support system can trigger a trace session in all NEs involved in a call path. Each NE then separately creates trace records responsive to various start and stop criteria and reports their trace records to the operations support system. The operations support system can attempt to correlate information within the trace records to trace a call from end-to-end, such as from a UE through a plurality of NEs to another UE. Such call tracing may allow determination of the root cause of call handling problems, optimization of resource usage and communication quality, and/or validation of interfaces between NEs.
Correlation of trace records from Universal Mobile Telecommunications System (UMTS) and Global System for Mobile Communications (GSM) based NEs has been possible using unique network-wide UE identities that are known to those NEs. However, in other systems, such as the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE), NEs do not have access to a unique network-wide UE identity, but only to temporary identities that can change over time. Consequently, an operations support system may not be able to correlate trace records through at least some system NEs and, therefore, may not be able to adequately trace a call from end-to-end.